JPH01294902A - Stator assembly of axial flow rotary machine - Google Patents

Abstract

PURPOSE: To restrain circumferential movement reasonably by forming a plurality of rails inside an annular outer case of a stator assembly and engaging leg portions formed integrally with a stator vane assembly with the rails in a specific structure. CONSTITUTION: An axial flow rotary machine has a stator assembly 14 and a rotor assembly 16. Rotor blade arrays 20, 22 extending to a position near the stator assembly 14 are arranged radially on a rotor disc 18 in the rotor assembly 16. The stator assembly 14 has arc-shaped stator vane assemblies 30, 32 arranged inside an annular outer case 24. In this case, rails 48, 50 are arranged in the outer case 24 along the flow direction. Each leg portion 54, 56 at upstream and downstream sides arranged in each of the assemblies 30, 32 is engaged with each of the rails 48, 50. At that time, a whirl stop key 58 arranged on the leg portion 56 at the downstream side is inserted into a space 74 formed in an outer air seal member 28 to restrain the circumferential movement.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a stator assembly having an annular component that seals against circumferential movement for use in axial flow rotating machines. Although the concept of the invention is used in the turbine and compression section of aircraft gas turbine engines, it can also be applied to rotating machinery in other fields.

[Prior Art] An example of an axial flow rotating machine is a gas turbine engine used to drive an aircraft. The engine primarily consists of a stator assembly and a rotor assembly. An annular working gas passage extends along the axis between the stator and rotor assembly toward the engine body.

The stator assembly consists of an outer case and a row of stator vanes extending inwardly from the outer case across the working gas flow path. The rotor assembly consists of rotor blades alternating with rotor and stator vane rows. Each row of rotor blades extends outwardly from the rotor across the working gas flow path and into close proximity to the outer case. The outer air seal extends inside the outer case and circumferentially around the outer surface of the rotor blade toward the gas flow path. The external air seal consists of multiple parts. Each member has an abradable surface, such as a honeycombed metallic material, that is subject to friction due to contact between the rotor blades and the external air seal during engine operation.

As the working gas flows along the flow path, the gas creates an axial and counterclockwise (as viewed from the front of the engine) force on the stator vanes. As the gas flow enters from the stator vane array into the vicinity of the rotor blade array, the external air seal will experience forces in an axial and clockwise direction or opposite to the circumferential force on the vanes.

Rotational resistance devices have been used to suppress circumferential movement of the stator vanes and external air seal members due to this circumferential force. One example is U.S. Pat. No. 4,687, issued to Aldo Prario.

No. 413 "Gas Turbine Engine Assembly" is mentioned. The feature of this device is to provide a C
The purpose is to join the rail to the rail using a molded coupler as a key. The C-type coupler covers the rear leg of the stator vane and the rail to horizontally connect the stator vane to the external air seal and the rail. The coupler is installed in a trickle direction between the rail and the external air seal.

Additionally, in a rotational resistance device such as that seen in U.S. Pat. No. 4,687,413, a stator vane array is restrained by a pin that is integrally constructed with an external air seal. Although such pins are very expensive, they are effective in ensuring safety within the gas flow path.

[Problems to be Solved by the Invention] In the conventional technology, the detent key is disengaged and the key protrudes into the gas flow path due to the coupling of force acting on the key that restrains the stator vane and the external air seal in the circumferential direction. I had something to do. Also, mounting such a key on a rail creates circumferential shear forces that are caused by the size of the bearing area of the key on the rail and by the vanes and external air seals that cause the key to fall into the slot. Coupling with the force generated by twisting the rail puts excessive stress on the rail.

In order to prevent damage to the various members of the vane assembly that are susceptible to displacement when a sudden force is applied to the vane, it is desirable to arrange the vane assembly in a straight line.

Also, a device is needed to assist in positioning the stator vane assembly in a straight line.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to seal the circumferential movement of the gas flow path members, namely the stator vane assembly and the external air seal, to simplify the design, to maintain rotational resistance devices against damage to the gas flow path, and to maintain a straight line. The object of the present invention is to provide such a device that can be placed on top of the device.

[Means for Solving the Problems] In order to achieve the above object, a stator vane assembly according to the present invention includes a set of rails disposed in an axial direction in an outer case, and a first rail in a first direction. a stator vane assembly having a first leg that joins a rail in a second direction and a second leg that joins a second rail in a second direction; an annular groove having a first diameter of , and a second rail having a diameter greater than the first diameter. an edge extending in the rail in a trickle direction and joining the second leg in the radial direction; an end extending in the radial direction and joining the second leg in the axial direction; and a circumference disposed on the vane. An axially extending slot installed in the rail is arranged to mate with the stop key. Further, the key has an integral structure with the second leg and extends in the axial direction from the vane,
installed with a radially extending protrusion on the outside of the key, the first leg is joined to the groove of the first rail, and the radial protrusion on the key protrudes at least a certain distance within the slot so that the key is in a straight line; Secure the vane to the case by twisting the vane outward about the first leg, inserting the key into the slot, and twisting the second leg axially to the end of the second rail.
The vanes are disposed axially outwardly by locating the first leg axially and radially relative to the first rail radially at the edge.

In addition, an elastic material made of an insulator such as ceramic fiber covered with metal is placed between the vane leg and the outer case to shield the gas inside the engine from leaking into the outer case and prevent collision force from being applied to the vane. The resulting compression on the elastic material exerts a force on the second rail.

The stator vane assembly includes a first portion having a key extending from the vane in the axial flow direction and having an integral structure with the vane, and a first portion for circumferentially joining the vane to the support structure to seal the circumferential movement of the vane. A key is provided that includes a second portion having a radial protrusion with an increased circumferential surface and a third portion extending from the second portion of the key and disposed in the axial direction near the arc member. , forming at least one radially extending wing. Furthermore, the radial projection of the key has a triangular cross section.

Further, an annular support structure having a plurality of slots extending in the axial direction facing the gas flow path is installed, the slots are arranged on the circumference of the support structure, and each arcuate member has the slot, axially from the first portion, comprising a first portion integral with the member, and a radial protrusion extending toward the support member, sealing circumferential movement and increasing the circumferentially facing area; an annular flow path for the working gas along the axis of symmetry and an annular flow path for the working gas, with a plurality of arcuate members extending and having a second portion disposed on the slot, which form an annular component to the gas flow path; form.

Further, the key of the annular component is provided with a third portion extending from the second portion, and the stator assembly is provided with a second annular portion facing a gas flow path axially proximate to the first annular component. a second annular component, each having a slot in the second annular component, the slot having a second arcuate member axially horizontally joined to the third portion of the key and circumferentially adjacent the second annular component; A plurality of second arc-shaped members are formed with gaps that prevent movement of the members in the circumferential direction. The first annular component is an array of stator vanes and the second annular component is an external air seal.

The stator assembly has an axis of symmetry Ar, an outer case is arranged in the circumferential direction of the axis of symmetry Ar, a rail is arranged circumferentially inside the case, and an inner contact surface on the rail and an inner contact surface on the contact surface. The annular array of stator vane assemblies is fitted into the case by installing a plurality of axial slots in the case and a circumferentially extending groove flanking the outer contact surface of the rail to join the rail to the outer air seal. at least a stator vane having an edge extending above the rail, a first portion integral with the vane and a second portion disposed within the slot and joining horizontally with the rail in the axial direction. and a third portion extending from the slot and installed in the key so as to join with the external air seal member, and forming an annular external air seal adjacent to the axial flow direction of the rail from the plurality of external air seal members. do. Each member has an upstream end and a downstream end with respect to the axial flow, and at least one member includes a circumferentially extending channel at one end facing the axial direction; a set of radially disposed edges extending in the direction and a plate extending between the edges to connect the channels, and horizontally joining the plate to the third portion of the key; Provide a void. The inner edge of the outer air seal covers the vane so that the vane and the outer air seal shield the rail from working gases, and the inner edge and outer edge of the air seal member cover the outer contact surface on the rail. Capturing the vanes on the rails with radial coverage in the flow direction radially constrains the rails at the edges of the vanes and radially constrains the external air seals at the outer contact surfaces of the rails.

Further, a first part of the key is disposed in the slot of the vane and joined to the vane integrally with a thickness t and a circumferential width w1, and a second part of the key is connected to the vane with a thickness t and a circumferential width w1. a second portion extending radially toward the outer case with an equal or smaller circumferential width W increasing the average thickness to greater than said t, and a third portion of the key having a thickness t and extending radially toward the outer case; It is installed so that it has a narrower circumferential width than the circumferential width W of the second portion.

The edge of the rail has an annular end extending inward from the inner contact surface of the rail, and a slot in the rail extends radially outward from the inner contact surface of the edge through the end on the rail. Install it so that it extends toward the target.

Furthermore, the key is integrally formed by being joined to the stator vane by soldering.

[Operation] When gas flows into the stator assembly of the axial flow gas turbine engine configured as described above, the key, which is integrally constructed with the vane, restrains the rail, the vane, and the external air seal, causing the vane and external air seal member to The integrated vane and key provide an axial force on the rail that resists the torsional force exerted circumferentially through the key by the external air seal and vane. It works like this.

[Examples] Hereinafter, the features of the present invention described above will be specifically explained in detail in preferred embodiments with reference to the accompanying drawings.

FIG. 1 shows a portion 10 of a turbine section of an axial flow rotating machine such as a gas turbine engine. The engine has an axis of symmetry Ar and an annular gas flow path 12 for hot working gas to flow along the axis towards the engine.

This gas moves within the turbine section at high speed and high pressure.

The engine includes a stator assembly 14 and a rotor assembly 1.
6 is installed. The rotor assembly includes a rotor disk, such as rotor disk 18.

Rotor blade rows 20 and 22 are mounted on each disk radially from the disk beyond the working gas flow path in close proximity to the stator assembly.

The stator assembly 14 has an annular support structure, such as an outer case 24, circumferentially about the axis toward the working gas flow path 12. An annular element, such as an external air seal 26, is placed radially outside the rotor blade to seal off the flow of working gas around the rotor blade and to shield the external case from hot gases.

Each outer air seal is comprised of a plurality of arcuate outer air seal members, such as outer air seal member 28.

Other annular elements facing the gas flow path include arcuate stator vane assemblies such as stator vane assemblies 30 and 32 disposed circumferentially within the outer case. The constituent material of the stator vanes includes AMS (Aerospace Material Specification) Standard 5391, which is a nickel-based alloy. During installation, the stator vanes are located as shown by the dotted lines in the drawings.

Each stator vane assembly 30 consists of a stator vane 33 having an inner platform 34 and an outer platform 36. Located between the platforms are one or more vanes 38 that extend radially across the gas flow path. An internal air seal 40 is joined to the outer platform and positioned circumferentially in close proximity to the rotor assembly.

A resilient insulation blanket 42 is packed between the stator vanes 30 and the outer case 24. The resilient insulation blanket consists of a ceramic fiber insulation layer 44 and an outer metallization layer.

The outer case 24 has a plurality of rails or case edges arranged in the axial direction as shown in the upstream rail 48 and downstream rail 50 and adjacent rail 52 with respect to the gas flow. One suitable material of construction for the rail is AMS Standard 5662, a nickel-based alloy. Each rail is installed circumferentially along the interior of the outer case. These rails have external air seals 28
Alternatively, it may be joined to the case to connect other stator assembly components, such as stator vane assembly 30. For example, the stator vane 33 is connected to the upstream rail 48
It has an upstream edge or leg 54 that connects with the rail 50 and a downstream edge or leg 56 that connects with the downstream rail 50 .

Each arcuate stator vane assembly is provided with a detent key 58 that is integrally constructed with the vane. One suitable constituent material for the key is AMS Standard 5391, a nickel-based alloy. The rail has a plurality of slots as shown in the axially disposed slots 60 that join the detent key and external air seal member on each stator vane to the rail. Place the key so that it fits into the slot on the rail. The key extends beyond the slot and is joined to member 28 near outer air seal 26.

Each member 28 of external air seal 26 has an upstream end 62 and a downstream end 64. The downstream end is
The stator vane assembly 32 is captured between the stator vane assembly 32 and the rail. The upstream end faces axially and connects the external air seal to the vane edge or leg 56 and the rail 5.
It is arranged on the circumference of the channel 66 connected to 0.

As shown in FIG. 1 and FIG. 2, which is an enlarged portion of FIG. 1, the external air seal member includes a set of edges (i.e., , an inner edge 68 and an outer edge 70). A plate 72 is disposed between the outer air seal edges facing the channel. The plate has a gap 74 that joins the external air seal member 28 to the key 58 that is integral with the vane. The key is
Insert into slot 60 on the rail. The plate portion slides the key horizontally in the axial direction and connects the key adjacently in the circumferential direction.

In this way, the downstream leg of the vane extends over the rail and forms a partial seal of the rail.

The inner edge of the outer air seal extends over the end on the rail and covers the vane leg to complete the rail seal.

The outer edge of the outer air seal is inserted into a groove 98 in the rail to seal the radial movement of the outer air seal, and the inner edge of the outer air seal seals the radial movement of the downstream vane leg. is sealed radially.

FIG. 3 shows an exploded perspective view of the three components shown in FIG. 1.

In particular, FIG. 3 shows the relationship of the vane assembly array of stator vane assembly 30 to outer case 24 and downstream outer air seal 28 to each other. The stator vane has a slot 7 for installing a key 58 in the vane.
Install 6. Key 58 has a first portion 78 in a slot in the vane. The key is made into an integral structure with the vane by mechanically joining it with adhesive or fasteners. An example of bonding is by soldering using materials such as AMS standard 4777 nickel solder material. The key has a thickness t and a width W, or W, in the range indicated by the dotted line in the circumferential direction.

Key 58 has a second portion 80 disposed within a slot 60 disposed in the rail. This second part has the same width W as the width W of the first part. In an example where the width of the second portion is narrower than that of the first portion, a wider width w is applied to the first portion. The second part has a radial projection towards the outer case of increasing average thickness as indicated by 1-, which is greater than the thickness t of the second part. This protrusion 8
2 increases the circumferential contact area and bearing area of the key to the rail.

The key is further arranged with a third portion 84 having a thickness t and a width less than the circumferential width W. The third portion is rounded at the circumferential end to size the void within the outer air seal and reduce force concentration within the upstream end of the outer air seal member 28.

A rail 50 extending circumferentially on the outer case 24 is provided with an edge 86 having an inner contact surface 88 that joins the rail with an outer surface 90 of the leg 36 of the stator vane assembly 32 . The edge 86 includes an annular end 92 extending radially from the inner contact surface 88 of the clamp toward the inside of the outer case. The end has a surface 94 that extends radially axially toward the upstream side and is positioned at the edge 86 to mate with a downstream surface 96 on the leg of the stator vane assembly. A slot receiving the second portion 80 of the key 58 extends into the end on the rail and is positioned upstream and out of the surface 88 on the leg.

The edge 86 of the rail is disposed from the remainder of the rail to form a groove 98 that extends circumferentially within the rail and has a contact surface in the downstream direction. This groove is installed in the rail to receive the outer edge 70 of the outer air seal 28.

The outer contact surface 100 on the rail faces the groove and horizontally joins the outer edge of the outer air seal.

The dotted line part in Figure 1 and Figure 4 show the stator vane assembly 32 and rail 50 when assembling the vane to the rail.
It also shows the relationship between the insulation blanket 42 and the insulation blanket 42. A slot 60 in the rail extends radially outwardly beyond the inner contact surface 88 of the edge 86 . The slot takes on an arcuate configuration due to the use of a friction wheel in forming the slot. Alternatively, the slot could be a machined planar surface. −
Structurally, the triangular-shaped radial protrusion 82 of the key 58 is disposed within the slot during assembly. The dotted line in Figure 1 indicates that prior to installation, the assembly force FA (shown in Figure 4) is suddenly applied to the rear of the vane, causing the vane to rotate around the upstream leg, causing the downstream side to rotate. The approximate positions assumed by the legs and keys are shown. As discussed below, forces acting axially forward and radially outwardly force the rear contact surfaces of vanes 90 and 96 to move between the end axial contact surfaces 94 and the inner side of the rail. firmly engages the contact surface 88 of the

When assembling the vanes to the rail, the stator vane assembly 32 is pivoted about the upstream leg 54 until the rear leg compresses the resilient insulator 42, as shown in FIG. Rotate to. The vane is rotated downwardly into the position shown in dotted lines such that the radial projection on the key extends at least a predetermined distance into the slot so that the vane and key are aligned with the rail. At this point, a sudden force is required to be applied to the arcuate groove 102 in the rail 48 to overcome the frictional force created by the insertion of the forward leg of the arcuate vane leg. This frictional force is caused by the fact that the arcuate surfaces of the legs (the vanes are installed at an angle, as shown by the dotted line in Figure 1) and the arcuate surfaces of the grooves in the rail are not aligned. caused by. The vanes are moved forward and outward by a sudden force FA applied by the use of a lever or rotating arm or by pressing suddenly against the rear leg of the vane an object with an elastic surface that does not damage the plastic filler or vane. . This resists forces that tend to compress the elastic insulator and cause it to become non-linear, ensuring that the vane is inserted firmly into place and that the insulator brings the rear leg of the vane into contact with the rail's axial contact surface. The vanes are moved forward and outward so as to apply pressure from the rear.

[Effects of the Invention] When driving a gas turbine engine as shown in FIG. 1, working gas flows along the gas flow path of the turbine. This gas flow creates an axial aft force P+a and a counterclockwise circumferential force F, c when viewed from the front of the engine on the vane blades. Figure 1 shows these forces, and Figure 3 shows the forces transmitted to the outer case via the rails.

As the working gas exits the vane, it creates an axial force F,a and a circumferential force Ftc acting on the external air seal in a clockwise direction as viewed from the front of the engine. Therefore,
The circumferential forces created on the vanes and the external air seal act in opposite directions at the key 2, resulting in a resultant force F + c - F tc
form. The shear forces caused by the keys on the rail are reduced by these opposing forces. The axial force F+a of the stator vane does not couple because the key is integrated with the vane. Therefore, the structure that connects the vane and the external air seal horizontally in the axial flow direction is
Compared to partially reducing the torsional moment or force, the torsional force caused by the resultant force F,c-F,c is reduced by forming the key integrally with the vane. In addition, the radial protrusion of the key increases the circumferential contact surface of the key, thereby reducing the stress between the members on the rail. This increases the fatigue life of the rail, which was short cycled. Also, by sealing the rails from hot gas flow with external air seals and vanes, thermal stress on the rails can be reduced.

Additionally, by forming the key 58 integrally with the stator vane 33 (either forming the key as part of the vane or forming the key separately and integrally joining the vane), the key It is possible to prevent the gas flow path from protruding out of the slot 60 and creating twisting or twisting forces. The reduction in shear forces and torsional movements allows the cross-sectional area of the key to be smaller for the same stress level in the rail. This reduces the bulk of the key and prevents parts of the key from breaking and protruding into the gas flow path.

Furthermore, by making the key integral with the vane, during assembly, it is possible to omit the effort of installing the key as a separate member on the vane and the external air seal after the vane is installed on the engine. That is, since it is not necessary to install the key as a partial member in a narrow area inside the engine, it is possible to reduce the number of parts for assembling the engine and simplify the final assembly.

Note that the adaptation of the present invention is not limited to the illustrated embodiments, but may be implemented in all possible modifications without departing from the gist of the present invention as stated in the claims. It is.

[Brief explanation of the drawing]

In the illustrated drawings, FIG. 1 is a simplified cross-sectional view of a turbine section of a gas turbine engine having an outer case and a support structure such as a stator vane row extending inward from the outer case, and FIG. is an enlarged view of a part of Figure 1; Figure 3 is a part of the stator vane row and part of the outer case with slots on the circumferentially extending rail, and a part of the outer case installed integrally with the vane. Figure 4 is an enlarged exploded perspective view of a part of the external air seal that has a gap for inserting the key. FIG. 3 is an enlarged cross-sectional view of the vane rotated in a direction. 10... Part of the turbine section of an axial flow rotating machine 12 - Gas flow path 14 - Stator assembly 16 - Rotor assembly 1
8-Rotor disk 20.22-Rotor blade row
24-External case 26-External air seal 28-External air seal member 30.32-Stator vane assembly 33-・Stator vane 38-Stator blade 42-Elastic insulator blanket 44-・Insulator layer 50-・Downstream rail 54- Upstream leg 56 - downstream leg
58-Detent key 60-Slot 74-Gap
78-First portion 80-Second portion 82-Radial projection 84-Third portion 86-Edge 92 One end 74
- air gap 82 - radial central origin

Claims (11)

[Claims] (1) A pair of rails arranged in the external case to be spaced apart in the axial flow direction, a first leg that connects to the first rail in a first direction, and a second rail that connects to the first rail in a second direction. a stator vane assembly having a mating second leg, the first rail having an annular groove having a first diameter into which the first leg fits; The rail has an annular groove having a diameter greater than the first diameter, an edge extending in the axial direction and joining the second leg in the radial direction, and an edge extending in the radial direction and joining the second leg in the radial direction. for assembling a stator assembly having flowwise mating ends and an axially extending slot disposed in a rail for mating with a detent key disposed on the vane; A protrusion extending in the axial direction and protruding outward in the radial direction is integrally formed on the second leg, the first leg is joined to the groove of the first rail, and the radial protrusion of the key is inserted into the slot. rotating outwardly about a first leg to a rotated position in which the vane protrudes at least a predetermined length and is aligned with the slot; A first leg is axially and radially engaged with the first rail, the key is inserted into the slot, and the second leg is axially engaged with the end. A method of assembling a stator assembly for a gas turbine engine, the method comprising: radially engaging the edges. 2. The gas turbine engine of claim 1, wherein an elastic material is disposed between the vane leg and the outer case, and compression of the vane against the elastic material applies a force to the second rail. How to assemble the stator assembly. (3) The stator vane assembly includes a first part in which a key extending from the vane in the axial direction has an integral structure with the vane, and a vane is circumferentially joined to a support structure to control movement of the vane in the circumferential direction. a second portion having a radial protrusion with an increased circumferential surface for sealing; and a third portion extending from the second portion of the key and extending in the axial direction near the arcuate member. 1. An arcuate stator vane assembly for use in a gas turbine engine, the arcuate stator vane assembly having at least one radially extending wing having a key of at least one radially extending vane. (4) The arcuate stator vane assembly according to claim 3, wherein the radial projection of the key has a triangular cross section. (5) The annular support structure has a plurality of slots extending in the axial direction facing the gas flow path, the slots are arranged on the circumference of the support structure, and each arcuate member has the slots. , a first part that is integrated with the member, and a radial protrusion that suppresses circumferential movement and increases the area facing the circumferential direction and extends toward the support member, from the first part in the axial flow direction. a plurality of arcuate members forming an annular component to the gas flow path and having a second portion extending over the slot and a second portion disposed over the slot;
A stator assembly for an axial flow rotating machine characterized by having an axis of symmetry and an annular flow path for working gas along the axis. (6) the annular component has a third portion with a key extending from the second portion; the stator assembly further includes a third portion facing the gas flow path axially proximate the first annular component; two annular components each having a slot, one slot horizontally joining the second arcuate member to the third portion of the key in an axial direction; 6. The stator assembly of claim 5, further comprising a plurality of second arcuate members having voids adjacent thereto for sealing circumferential movement of the members. 7. The stator assembly of claim 6, wherein said first annular component is a row of stator vanes and said second annular component is an external air seal. (8) It has an axis of symmetry Ar, an outer case extends in the circumferential direction of the axis of symmetry Ar, and has a rail extending circumferentially inside the case, and the rail connects to the inner contact surface and the outer case. an annular row of stator vane assemblies having a plurality of axial slots on the contact surface and a groove extending circumferentially flanking the outer contact surface of the rail to join the rail to the external air seal; installed circumferentially inside the case, at least the stator vanes have edges extending over the rails, and the key is installed in the slot with a first portion integral with the vanes and parallel to the rails in an axial direction; an annular outer air seal proximate in the axial direction of the rail from the plurality of external air seal members; each member has an upstream end and a downstream end with respect to the axial flow, and at least one member has a circumferentially extending channel at one end facing the axial flow direction; a pair of radially disposed edges extending in the flow direction, a plate extending between the edges to connect the channels, and a gap horizontally joining the plate with a third portion of the key. and the inner edge of the outer air seal covers the vane so that the vane and the outer air seal shield the rail from working gas, and the inner edge and outer edge of the air seal member are in contact with the outer side on the rail. By trapping the vane on the rail by covering the surface radially in the axial direction, the rail is radially restrained by the edge of the vane,
The outer contact surface of the rail radially constrains the outer air seal, the rail and key sealing circumferential movement of the vane and outer air seal member, and the integrated vane and key constrain the outer air seal and the vane to restrain circumferential movement of the outer air seal. A stator assembly for a gas turbine engine characterized in that it provides an axial force on the rails that resists torsional forces generated circumferentially through the rail. (9) the vane has a slot, a first portion of the key being disposed within the slot and integrally joined to the vane with a thickness t and a circumferential width w_1; The second portion extends radially in the direction of the outer case with a width w in the circumferential direction that is equal to or narrower than the w_1, thereby increasing the average thickness of the second portion so that the average thickness becomes larger than the t, Claim 8, characterized in that the third part of the key is arranged to have a thickness t and a circumferential width narrower than the circumferential width w of the second part.
A stator assembly for a gas turbine engine as described in . (10) The edge of the rail has an annular end extending inwardly from the inner contact surface of the rail, and a slot in the rail extends the end from the inner contact surface of the edge on the rail. 10. The gas turbine engine stator assembly of claim 9, wherein the stator assembly extends radially outwardly through the stator. (11) The stator assembly for a gas turbine engine according to claim 9, wherein the key is joined to the stator vane by soldering.